Including Heating Or Cooling Details Patents (Class 117/222)
  • Patent number: 5843228
    Abstract: The invention is directed to preventing meltdown of conductive metal electrodes 5, 5 used to supply current to a heater 104 of a crucible 103. A single crystal pulling apparatus comprises: the heater 104 which encircles the crucible 103, and the pair of electrodes 5, 5, respectively threaded to a pair of graphite intermediate electrodes 6 of the heater 104, and a voltage source 9 for supplying power to the pair of electrodes 5, 5. A switch 11 switches the power on and off. A watthour meter 10a, continuously measures the current flowing through the heater 104. Investigation by the present inventors showed that in the case of a crack 8 in a lower portion of the intermediate electrode 6, minute fluctuations occurred in the measured value of the current, arising from an electric discharge phenomena in the crack 8 prior to meltdown of the electrodes 5, 5.
    Type: Grant
    Filed: April 1, 1997
    Date of Patent: December 1, 1998
    Assignees: Mitsubishi Materials Silicon Corporation, Mitsubishi Materials Corporation
    Inventors: Masao Saitoh, Daisuke Wakabayashi, Takashi Atami, Hisashi Furuya
  • Patent number: 5827367
    Abstract: An apparatus and method for growing large diameter silicon crystals using the Czochralski (Cz) method, wherein the neck section of the crystal is significantly strengthened to eliminate the risk of breakage in the neck section, by providing a heat shield assembly which is located adjacent to the neck section and ascends in conjunction therewith to force the cooling gas directly onto the neck section of the silicon ingot.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: October 27, 1998
    Assignee: SEH America
    Inventors: Witawat Wijaranakula, Akihiko Tamura
  • Patent number: 5824149
    Abstract: An enclosing structure extends into a transition zone of a crystal growing system through which the growing crystal is pulled. One or more independent temperature control devices are secured to the inside surface of the enclosing structure, which control devices sense crystal temperature and supply to, or extract heat from, the crystal so that a carefully-controlled thermal gradient can be established either radially or longitudinally in the crystal. The temperature control devices may include temperature sensors that provide temperature information to a central control device connected to each temperature control device. The enclosing structure may have a hollow wall structure through which a heat exchange fluid, such as water, is passed to extract heat from the transition chamber and crystal. The temperature control apparatus may also be segmented so that each segment can be controlled independently of the remaining segments thereby permitting independent control to be effected at different crystal areas.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: October 20, 1998
    Assignee: Ferrofluidics Corporation
    Inventor: Zhixin Li
  • Patent number: 5817171
    Abstract: A puller and method for crystal growth using the Czochralski technique in which a temperature profile and a history of thermal conditions of a growing crystal is controllable with ease and a good accuracy, which puller comprises a crucible containing raw material, heater for melting by heating the raw material and a heat insulating cylinder surrounding them, the heat insulating cylinder being cross-sectionally divided by an annular separation gap or gaps into parts and which method is applicable to growth of such a single crystal as of silicon, germanium, GaP, GaAs or InP in the puller. Methods for controlling a temperature profile and a history of thermal conditions of a growing crystal using the czochralski technique in the puller.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: October 6, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masahiro Sakurada, Tomohiko Oota, Kiyotaka Takano, Masanori Kimura
  • Patent number: 5795383
    Abstract: A method and a mechanism for lifting a gas flow-guide cylinder of a crystal pulling apparatus are disclosed. The crystal pulling apparatus includes a crucible for accommodating a crystalline material and for melting the crystalline material through heating, and a gas flow-guide cylinder capable of being moved upward/downward above the crucible. The crystal pulling apparatus is operated to grow a single crystal from the crystalline material by a pulling method. When a solid crystalline material is to be placed in the crucible, the gas flow-guide cylinder is moved upward to thereby separate the bottom end of the gas flow-guide cylinder away from the top portion of the crucible. This prevents the crystalline material from coming into contact with the gas flow-guide cylinder.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: August 18, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Hideo Okamoto, Toshiharu Uesugi, Atsushi Iwasaki, Tetsuhiro Oda
  • Patent number: 5792258
    Abstract: A high-frequency induction heater for use in the growth of a semiconductor single crystal by the FZ method, including a plurality of high-frequency induction heating coils disposed in concentric juxtaposed relation to each other and each having a pair of power supply terminals provided for supplying a high-frequency current to the associated heating coil, with the power supply terminals of one of the heating coils being disposed in a space defined between opposite ends of an adjacent heating coil disposed outside the one heating coil, wherein a pair of electrically conductive members is attached to the pair of power supply terminals, respectively, of at least an innermost one of the heating coils so as to cover a space defined between the power supply terminals of the innermost heating coil. With the induction heater thus constructed, the so-called "pulsation", i.e.
    Type: Grant
    Filed: January 29, 1996
    Date of Patent: August 11, 1998
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Masanori Kimura, Ken Yoshizawa, Teruaki Fukami, Hirotoshi Yamagishi
  • Patent number: 5785757
    Abstract: The present invention provides a method and an apparatus for fabricating a single-crystal semiconductor by means of the CZ method in which the oxygen concentration in the single-crystal semiconductor is controlled within an acceptable range. The apparatus comprises a regulating cylinder concentrically covering the single-crystal semiconductor which is pulled from a melt in a crucible; a main chamber for isolating the growing single-crystal semiconductor from external atmosphere; and a falling gas introducing means on top of the main chamber for introducing an inert gas into the main chamber. The apparatus is characterized in that a whirling gas introducing means on a circumferential portion of the main chamber introduces an whirling inert gas into the main chamber in a tangential direction to the side walls of the main chamber and the regulating cylinder.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: July 28, 1998
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventor: Yoshinobu Hiraishi
  • Patent number: 5766347
    Abstract: An apparatus for fabricating a semiconductor single crystal, which make it possible to reduce the oxygen concentration of a pulling single crystal, to steadily dissolve the polysilicon material received in a crucible, and to minimize the cost and installation space, is provided.The hollow cylindrical resistance heater of the apparatus, which co-axially surrounds a crucible, is provided with a ring-shaped slit excluding the location where at least two electrodes are formed, in a direction substantially perpendicular to the axial direction so as to divide the heater into an upper heating portion and a lower heating portion, and is provided with a plurality of vertical slits formed on the upper heating portion and the lower heating portion respectively, in a direction substantially parallel to the axial direction, wherein each vertical slit formed on the upper heating portion does not align with each vertical slit formed on the lower heating portion.
    Type: Grant
    Filed: February 24, 1997
    Date of Patent: June 16, 1998
    Assignee: Komatsu Electronic Metals Co., Ltd.
    Inventors: Koichi Shimomura, Yoshinobu Hiraishi, Mitsunori Kawabata
  • Patent number: 5759261
    Abstract: A method and an apparatus for pulling a silicon monocrystal from a melt iudes the pulling of a conical portion in each case at the beginning and at the end of the monocrystal and the pulling of a cylindrical portion between the conical portions. In this method, the surface of the conical portion at the beginning of the monocrystal is shielded by a shielding means spaced apart from the monocrystal.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: June 2, 1998
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventors: Erich Dornberger, Wilfried Von Ammon
  • Patent number: 5746828
    Abstract: A crystal-pulling apparatus incorporates a temperature sensor and an adjustable radiation shield. The temperature sensor measures temperatures of a melt surface adjacent to a solidification interface between a crystal and the melt. The radiation shield regulates radiational cooling of the melt. A control system adjusts the radiation shield in response to changes in the measured temperature of the melt for enhancing dislocation-free growth of the crystal.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: May 5, 1998
    Assignee: General Signal Corporation
    Inventor: Anatoli S. Boulaev
  • Patent number: 5746824
    Abstract: An apparatus and a method are provided for producing a silicon single crystal in an inert-gas flushed pulling chamber by pulling the single crystal from a melt by the Czochralski method. The method includes a) providing in the pulling chamber a first inner chamber and a second inner chamber, each of which is delineated by side, top and bottom boundaries; b) passing a first inert gas stream through the top boundary of the first inner chamber into the first inner chamber, which contains a heat shield, which is disposed around the single crystal, and a crucible containing the melt, and c) passing a second inert gas stream through the bottom boundary of the second inner chamber into the second inner chamber, which contains a heating device for heating the crucible, with the proviso that the first inert gas stream and the second inert gas stream are only able to mix, at the earliest, after leaving the inner chambers.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: May 5, 1998
    Assignee: Wacker Siltronic Gesellschaft fur Halbeitermaterialien AG
    Inventor: Friedrich Nemetz
  • Patent number: 5741359
    Abstract: An apparatus for zone-melting recrystallization of a semiconductor layer includes a first heater, on which a semiconductor wafer including the semiconductor layer and upper and lower insulating films sandwiching the semiconductor layer is mounted, for radiantly heating a rear surface of the semiconductor wafer to a temperature at which the semiconductor layer and the insulating layers are not melted; and a second heater disposed above the semiconductor wafer and radiantly heating a front surface of the semiconductor wafer. The second heater has a heat generating point that produces a heated spot in the semiconductor layer and moves spirally while maintaining a fixed distance from the semiconductor wafer, thereby producing a large-area monocrystalline region in the semiconductor layer. In this zone-melting recrystallization, a single crystalline nucleus is produced in the semiconductor layer, and the entire semiconductor layer is recrystallized with the crystalline nucleus as a seed crystal.
    Type: Grant
    Filed: September 7, 1995
    Date of Patent: April 21, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Motoda, Manabu Kato
  • Patent number: 5707447
    Abstract: A crystal pulling apparatus for producing a crystal boule (17) from a material melted in a crucible (4) has, in a tank (1), a heater (5) surrounding the crucible (4). The tank (1) has in the area of the crucible (4) an annular chamber (8) defined on the heater (5) side by an inner protective wall (6) and connected to the shielding gas outlet (14, 15), and on the outside by an outer protective wall (7) behind which the thermal insulation (10) of the tank (1) is located.
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: January 13, 1998
    Assignee: Balzers und Leybold Deutschland Holding AG
    Inventors: Winfried Schulmann, Johann Scholler
  • Patent number: 5611857
    Abstract: A process and apparatus for producing silicon single crystals with excellent dielectric strength of gate oxide films by adjusting the temperature gradient of the pulled-up silicon single crystal without loss of its rate of pulling. The process of producing silicon single crystals by pulling up the single crystal from a melt of material of the single crystal imposes a certain average temperature gradient on the grown single crystal while it is still at high temperature. The apparatus is provided with a heating element outside a crucible and pulling shaft with which a single crystal is pulled up from the melt of the material in the crucible. The ratio of length h of the heating element to the inside diameter .phi. of the crucible is adjusted so as to be between 0.2 and 0.8 whereby the temperature gradient can be maintained below 2.5.degree. C./mm.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 18, 1997
    Assignee: Sumitomo Sitix Corporation
    Inventors: Yoshihiro Akashi, Kaoru Kuramochi, Setsuo Okamoto, Yasuji Tsujimoto, Makoto Ito
  • Patent number: 5607506
    Abstract: An improved system and process for growing crystal fibers comprising a means for creating a laser beam having a substantially constant intensity profile through its cross sectional area, means for directing the laser beam at a portion of solid feed material located within a fiber growth chamber to form molten feed material, means to support a seed fiber above the molten feed material, means to translate the seed fiber towards and away from the molten feed material so that the seed fiber can make contact with the molten feed material, fuse to the molten feed material and then be withdrawn away from the molten feed material whereby the molten feed material is drawn off in the form of a crystal fiber.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: March 4, 1997
    Assignee: University of South Florida
    Inventors: Vongvilay Phomsakha, Robert S. F. Chang, Nicholas I. Djeu
  • Patent number: 5578123
    Abstract: Apparatus for preparing a single crystal made of silicon is according to Czochralski method, which includes a tubular to the conical body which shields the growing single crystal and divides the receiver chamber above the melt into an inner portion and an outer portion, the body having at least one orifice through which inert gas which is conducted into the inner portion of the receiver chamber is able to pass directly into the outer portion of the receiver chamber. The method for preparing a single crystal made of silicon is in accordance with the Czochralski method, wherein a portion of an inert gas stream is conducted through at least one orifice in the tubular to conical body from the inner portion into the outer portion of the receiver chamber.
    Type: Grant
    Filed: October 10, 1995
    Date of Patent: November 26, 1996
    Assignee: Wacker Siltronic Gesellschaft fur Halbleitermaterialien AG
    Inventors: Peter Vilzmann, Helmut Pinzhoffer
  • Patent number: 5571320
    Abstract: The invention defines an apparatus for controlling oxygen content in Czochralski silicon crystal pullers in which silicon is melted in a quartz crucible. The apparatus includes a susceptor 10, a quartz crucible 12 in said susceptor, a cable 16 for lowering a seed crystal 14 into silicon melted in said crucible, and a combination spiral heater/magnetic coil 25 for heating and melting silicon in said crucible, and for producing a magnetic field around the crucible.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 5, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: H. Michael Grimes, Farouk A. Hariri
  • Patent number: 5551978
    Abstract: An apparatus for producing a single crystal comprising a heater which is arranged on the outer periphery of a crucible and movable along the axis of growth of a single crystal. The heater is moved along the direction of growth of the single crystal in accordance with the surface position of the molten liquid layer in the crucible. The apparatus for producing a single crystal further comprising means for adjusting the speed at which the seed crystal is pulled. For example, the pulling speed of the seed crystal is adjusted in accordance with the position of the heater.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: September 3, 1996
    Assignee: Sumitomo Sitix Corporation
    Inventors: Yoshihiro Akashi, Kaoru Takiuchi, Setsuo Okamoto
  • Patent number: 5394830
    Abstract: Apparatus and method are provided for growing improved quality long and large single crystals in a liquid encapsulated Czochralski (LEC) process, in which a separate cooling circuit is provided for the upper portion of a vessel which cools that portion independently of any cooling means for the lower portion of the vessel, and in which the gas flow pattern can desirably be controlled such that the gas flow is predominantly downward adjacent the vessel wall, and predominantly upward near the center of the vessel, where the crystal is being pulled from the melt.
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: March 7, 1995
    Assignee: General Electric Company
    Inventor: Farzin H. Azad
  • Patent number: 5394829
    Abstract: A device for pulling a silicon single crystal is constructed so as to preclude deposition of a SiO-derived substance on graphite parts inside the device and prevent the graphite parts from deterioration, elongate the duration of continuous use of the device in a great measure, and simplify the disassembly and reassembly of the device.This device pulls a silicon single crystal in an atmosphere of inert gas by the Czochralski method, which device is chracterized by comprising a crucible 1 for accommodating a molten silicon mass 2, a heater 3 disposed round the periphery of the crucible 1, an outer member 14 forming a pulling chamber 6 for accomodating the crucible 1, an inert gas inlet part 15 disposed in the upper part of the pulling chamber 6, and an inert gas outlet part 16 separated from the inert gas inlet part 15 in the same upper part of the pulling chamber 6.
    Type: Grant
    Filed: March 23, 1993
    Date of Patent: March 7, 1995
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventors: Toshiharu Uesugi, Koji Mizuishi, Atsushi Iwasaki, Tadashi Niwayama, Tetsuhiro Oda
  • Patent number: 5308594
    Abstract: Wafers of silicon-on-insulator (SOI) produced by the zone melting recrystallization technique are known to exhibit warping and edge defects which prohibit their use in automated silicon wafer processing equipment. These deficiencies arise from excess heat buildup at the periphery of the wafer because the wafer edge acts as a barrier to heat transfer. Dissipation of heat from the edge by varying the heat dissipation efficiency of the environment about the periphery of the wafer allows wafers with substantially fewer defects to be produced.
    Type: Grant
    Filed: September 10, 1992
    Date of Patent: May 3, 1994
    Assignee: Massachusetts Institute of Technology
    Inventor: Chenson K. Chen